[PATCH 2/2] nand_omap_gpmc: use 0x00 for ECC padding in BCH ROM mode

[Sascha Hauer]

On Tue, Jan 29, 2013 at 10:58:02AM +0100, Jan Luebbe wrote:
> The kernel uses these bytes to differentiate between erased/programmed
> pages.
> 
> Signed-off-by: Jan Luebbe <jlu at pengutronix.de>
> ---
>  drivers/mtd/nand/nand_omap_gpmc.c |   30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
> 
> diff --git a/drivers/mtd/nand/nand_omap_gpmc.c b/drivers/mtd/nand/nand_omap_gpmc.c
> index 9050a8d..b81ad53 100644
> --- a/drivers/mtd/nand/nand_omap_gpmc.c
> +++ b/drivers/mtd/nand/nand_omap_gpmc.c
> @@ -751,6 +751,35 @@ static int omap_gpmc_read_page_bch_rom_mode(struct mtd_info *mtd,
>  	return 0;
>  }
>  
> +static void omap_gpmc_write_page_bch_rom_mode(struct mtd_info *mtd, struct nand_chip *chip,
> +				  const uint8_t *buf)
> +{
> +	int i, eccsize = chip->ecc.size;
> +	int eccbytes = chip->ecc.bytes;
> +	int eccsteps = chip->ecc.steps;
> +	uint8_t *ecc_calc = chip->buffers->ecccalc;
> +	const uint8_t *p = buf;
> +	uint32_t *eccpos = chip->ecc.layout->eccpos;
> +
> +	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
> +		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
> +		chip->write_buf(mtd, p, eccsize);
> +		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
> +	}
> +
> +	for (i = 0; i < chip->ecc.total; i++)
> +		chip->oob_poi[eccpos[i]] = ecc_calc[i];
> +
> +	/*
> +	 * set padding byte for each subpage to 0x00, so the kernel
> +	 * can detect erased pages
> +	 */
> +	for (i = 0; i < 4; i++) {
> +		chip->oob_poi[1+14*(i+1)] = 0x00;
> +	}
> +
> +	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
> +}
>  static int omap_gpmc_eccmode(struct gpmc_nand_info *oinfo,
>  		enum gpmc_ecc_mode mode)
>  {

Nit: Missing blank line.

Sascha

> @@ -823,6 +852,7 @@ static int omap_gpmc_eccmode(struct gpmc_nand_info *oinfo,
>  		oinfo->nand.ecc.bytes    = 4 * 13;
>  		oinfo->nand.ecc.size     = 4 * 512;
>  		nand->ecc.read_page = omap_gpmc_read_page_bch_rom_mode;
> +		nand->ecc.write_page = omap_gpmc_write_page_bch_rom_mode;
>  		omap_oobinfo.oobfree->length = 0;
>  		j = 0;
>  		for (i = 2; i < 15; i++)
> -- 
> 1.7.10.4
> 
> 
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> 

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